Remove 'field' from 'value_to_html' method attributes
't-esc' escape the result of the widget.
(Added 'remove_span' as option for monetary widget)
E.g.: <t t-esc="32" t-options='t-options='{"widget": "monetary", "display_currency": website.currency_id, "remove_span": True}'>
result: $ 365.00